This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Background: Two grants (U24, U42) provide funding for derivation of the AIDS SPF colony. Methods: Initially animals were derived from the TNPRC conventional breeding colony. Animals are negative for SIV, STLV-1, SRV, and B-virus. All animals from the AIDS SPF colonies are limited to assignment to AIDS research projects. The census of the colony is approximately 2001, which meets projections. Seventy-one of the animals are assigned to the expanded SPF program. Results/Discussion: In 2010, 215 SPF rhesus were made available for assignment to affiliate and core investigators. In addition, piggybacked use of animals in the breeding colony occurred. Tissues, including blood, feces, saliva, and bone marrow, were provided to investigators to support their research programs. Behavioral/observational data were also collected to support research and management programs. All piggyback use of animals is noninvasive or minimally invasive and allows animals to remain in their social groups with no impact to production.